The present invention relates to a device for monitoring the coinage in coin tubes and more particularly to a device that uses acoustical means to sense certain coin movements in the monitoring of coinage in coin tubes to determine the number of coins in the coin tubes and to control where newly deposited coins are directed.
Many devices are in existence for monitoring the coinage in coin tubes to determine and control the number of coins remaining in coin tubes for making change and refunds from vending machines and for maintaining minimum numbers of coins in the tubes. For the most part, the known coin tube control and monitoring devices have included mechanical devices such as mechanical coin sensors or feelers which sense the presence of coins in the coin tubes, electric switches, optical devices, inductors, and Hall effect sensors which physically, electrically, optically, or magnetically sense the presence of coins in the coin tubes. Such devices typically operate on a go or no go basis in sensing the coins and/or the number of coins in a coin tube by the condition of the feeler or switch, or the presence or absence of a light beam, or the condition of a Hall effect device. Such devices have been used to determine if a coin tube has enough coins in it to be able to be operated to payout change to a customer. Some of these devices are located at the top, the bottom or at an intermediate location along the coin tube to sense the presence of coins. Additionally, those devices that use a sensor located at an intermediate location along the coin tube are used to limit the self-loading of the coin tube above the intermediate level. Mechanical feelers, switches, optical sensors, inductors, and Hall effect devices have obvious disadvantages and limitations including being subject to breaking, failing, sticking and interfering with coin movements. These devices are also relatively expensive and are slow acting as compared to electronic circuit devices and they are relatively susceptible to jamming and require frequent maintenance and repair. All of these conditions and limitations of the known monitoring devices limit their usefulness, cause relatively frequent repair and maintenance, and increase the cost of operating and maintaining the coin tubes, and particularly the coin tubes used for making change in a vending machine. Since the coin tubes in a vending machine are the usual means chosen for coins to be accumulated for payback it is important that the coin tubes be as clear and open as possible and free from maintenance and jamming. It is also important to know how many coins are in the coin tubes at all times in order to determine whether a deposited coin should be sent to one of the coin tubes or to a cash box.
One such device for monitoring the coinage in coin tubes is disclosed in U.S. Pat. No. 4,587,984, which is assigned to a subsidiary of the assignee of this invention. This device maintains a running total of the number of coins in one or more coin tubes by adding and substracting coins to establish an amount to be maintained which is predetermined. In order for this device to perform properly the predetermined number of coins store in each coin tube must be known. Data produced from other vending control means as a result of deposits made, coins paid back or refunded, and the difference between the number of coins deposited that are directed into the coin tubes and the number of coins that are passed to the cash box are used to determine the number of coins remaining in the coin tubes. A predetermined maximum and predetermined minimum number of coins to be accumulated in each of the coin tubes are also used to direct coins to a suitable location in the vending machine.
Another device for monitoring the coinage in coin tubes is shown in U.S. Pat. No. 4,491,140 whereby only one level of each coin tube is sensed to provide correction to the running total whenever its predetermined level detector indicates a change. This device maintains a running estimated count of the coins in a coin tube. This device also includes a sensor which determines whether the number of coins in the coin tube is greater than a predetermined number. If the number of coins in the coin tube is greater than the predetermined number the running estimated count is modified.
Various limitations of the prior art devices can be seen when considering the use of coin tubes having increased heights and numbers which result in increased storage capacities. It is desirable to provide flexability of coin tube maximum and minimum amounts as the requirements for making change varies from one sale price situation to another, and with the acceptance of certain coins and bill demoninations, i.e., unless the largest demomination coin is required, for making change if accepting higher denomination currency. Additionally, as the number of coin tubes increases due to differing requirements of vending machines, the prior art devices have to be modified to add more circuitry, especially replicative circuitry.